Seasonal accumulation of acetylated triacylglycerols by a freeze-tolerant insect.

Most animals store energy as long-chain triacylglycerols (lcTAGs). Trace amounts of acetylated triacylglycerols (acTAGs) have been reported in animals, but are not accumulated, likely because they have lower energy density than lcTAGs. Here we report that acTAGs comprise 36% of the neutral lipid pool of overwintering prepupae of the goldenrod gall fly, Eurosta solidaginis, while only 17% of the neutral lipid pool is made up of typical lcTAGs. These high concentrations of acTAGs, present only during winter, appear to be synthesized by E. solidaginis and are not found in other freeze-tolerant insects, nor in the plant host. The mixture of acTAGs found in E. solidaginis has a significantly lower melting point than equivalent lcTAGs, and thus remains liquid at temperatures at which E. solidaginis is frozen in the field, and depresses the melting point of aqueous solutions in a manner unusual for neutral lipids. We note that accumulation of acTAGs coincides with preparation for overwintering and the seasonal acquisition of freeze tolerance. This is the first observation of accumulation of acTAGs by an animal, and the first evidence of dynamic interconversion between acTAGs and lcTAGs during development and in response to stress.

Temporal changes of urinary oxidative metabolites of di(2-ethylhexyl)phthalate after the 2011 phthalate incident in Taiwanese children: findings of a six month follow-up.

A major incident involving phthalates-contaminated foodstuffs occurred in Taiwan in May 2011, leading to the quick removal of tainted food items from store shelves. We investigated changes in urinary oxidative di(2-ethylhexyl)phthalate (DEHP) metabolites, our proxy for exposure to DEHP-tainted foodstuffs in children ≤10 years, during the six months following withdrawal of the tainted food. Our hospital screened 60 possibly exposed children between May and June 2011. The children's food intake information was collected, and they were administered one-spot urine samples at baseline and at the two and six month follow-ups. All three samples were measured for four oxidative DEHP metabolites, mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono-(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP), and mono-(2-carboxymethylhexyl) phthalate (2cx-MMHP) by triple quadrupole liquid chromatography tandem mass spectrometry. Fifty-two children had been exposed. After excluding those without a full set of urine samples or adequate food intake information, 23 exposed children were studied. We found significantly positive correlations between DEHP daily intake and urinary 5OH-MEHP, 5oxo-MEHP, and 5cx-MEPP (p < 0.05). At the six month follow-up, all four metabolite concentrations had significantly decreased compared to the baseline. In conclusion, urinary DEHP metabolites decreased progressively in children after tainted food withdrawal, indicating that the main sources of phthalate contamination for children had been successfully controlled.

A Machine Learning Strategy for Drug Discovery Identifies Anti-Schistosomal Small Molecules.

Schistosomiasis is a chronic and painful disease of poverty caused by the flatworm parasite Schistosoma. Drug discovery for antischistosomal compounds predominantly employs in vitro whole organism (phenotypic) screens against two developmental stages of Schistosoma mansoni, post-infective larvae (somules) and adults. We generated two rule books and associated scoring systems to normalize 3898 phenotypic data points to enable machine learning. The data were used to generate eight Bayesian machine learning models with the Assay Central software according to parasite's developmental stage and experimental time point (≤24, 48, 72, and >72 h). The models helped predict 56 active and nonactive compounds from commercial compound libraries for testing. When these were screened against S. mansoni in vitro, the prediction accuracy for active and inactives was 61% and 56% for somules and adults, respectively; also, hit rates were 48% and 34%, respectively, far exceeding the typical 1-2% hit rate for traditional high throughput screens.

Intake of phthalate-tainted foods alters thyroid functions in Taiwanese children.

BACKGROUND: On April-May, 2011, two Taiwan chemical companies were found to have intentionally added phthalates, Di-(2-ethylhexyl) phthalate (DEHP) and/or Di-isononyl phthalate, as a substitute of emulsifier to many foodstuffs. This study aimed to investigate whether exposure to these foods altered endocrine functions in children aged ≤10 years and, if so, whether those changes could be reversed by stopping exposure. METHODS: One Phthalates Clinic for Children was established in southern Taiwan between May 31 and June 17, 2011. All eligible children had their exposure information, blood and/or urine specimens collected. Endocrine functions were assessed in serum. The exposure groups were categorized into three (High, >500 ppm, Low, 1-500 ppm, and No, <1 ppm of DEHP). After six months, some children were followed up for the selected endocrine hormones. RESULTS: Sixty children were eligible in this study; all were Tanner stage 1 with no pubic hair. Compared to non-exposed group, both high and low exposure groups had significantly lower serum thyroid-stimulating hormone (TSH) levels (P = 0.001 and 0.024). At six months follow-up, serum triiodothyronine (T3) levels was significantly changed (P = 0.034) in high exposure group (n = 13). For serum estradiol (E2), the detectable rate (≥8 pg/mL) decreased from 76.9% (10/13) to 30.8% (4/13) (P = 0.070). CONCLUSIONS: This study shows that serum TSH levels can be altered when children were exposed to high concentrations of phthalate-tainted foodstuffs. Serum E2 and T3 may be partially recovered after stopping exposure.

The public health threat of phthalate-tainted foodstuffs in Taiwan: the policies the government implemented and the lessons we learned.

A major incident of phthalate-contaminated foodstuffs happened in Taiwan between April and July, 2011. Phthalates were deliberately added to foodstuffs as a substitute of emulsifier. We describe the course of this incident, government response and management of the crisis, and its future implications. Five major food categories, including sports drinks, fruit beverages, tea drinks, fruit jam or jelly, and health food or supplements in tablet or powder form, were contaminated with Di-(2-ethylhexyl)phthalate and/or Di-isononyl phthalate. At least 900 different food products were affected. Like the scandal of melamine-tainted infant formula, this event represents another large deliberate food contamination incident. It is important to be reminded that many governments in developing countries make rapid economic growth as their first priority, often compromising environmental safety and public health. The administration leaders need to find a balance between economic expansion and health and environmental safety.